Sulfide Solid Electrolyte Halogen Doping for Resistance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sulfide solid electrolyte materials react with cathode active materials to form high resistive layers, increasing interface resistance, while incorporating fluorine can reduce this but also increases bulk resistance and decreases ion conductivity.
Innovation Solution
Incorporating chlorine (Cl) or bromine (Br) into the sulfide solid electrolyte material to balance the reduction of interface resistance with maintaining high ion conductivity, potentially using a core-ion conductive portion with a covered portion containing Cl or Br, and including iodine (I) to further stabilize the material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fluorine is incorporated into the sulfide solid electrolyte material to restrain interface resistance increase, then interface resistance is reduced, but bulk resistance increases and ion conductivity decreases
Solution Approach 1:
The patent changes the chemical composition parameters by substituting fluorine (F) with chlorine (Cl) or bromine (Br) atoms in the sulfide solid electrolyte material. This parameter change modifies the material's chemical properties to achieve a different balance between interface stability and bulk ion conductivity, resolving the contradiction by finding an alternative halogen element that does not increase bulk resistance while still restraining interface resistance increase.
Solution Approach 2:
The patent creates a composite sulfide solid electrolyte material containing multiple elements (Li, P, S, Cl/Br, and optionally F). By combining these elements in specific ratios, the material achieves both low interface resistance and maintained bulk conductivity. The composite structure allows different elements to fulfill different functions: Cl/Br for interface stability and S for bulk ion conduction pathways.
2Reliability
If sulfide solid electrolyte material is used to achieve high Li ion conductivity, then ion conductivity is improved, but reaction with cathode active material forms high resistive layer increasing interface resistance
Solution Approach 1:
The patent modifies the chemical composition parameters of the sulfide solid electrolyte by incorporating Cl or Br elements in specific amounts (0.1-10 mol%). This parameter change alters the material's reactivity characteristics, reducing its tendency to form high resistive layers with cathode active materials while preserving the high ion conductivity provided by the sulfide matrix structure.
Solution Approach 2:
The patent converts the harmful reaction between sulfide electrolyte and cathode material into a beneficial effect. By controlling the composition to include Cl or Br, the initial reaction forms a stable interface layer that prevents further detrimental reactions. This controlled interfacial reaction, rather than being purely harmful, creates a protective barrier that maintains long-term interface resistance stability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The use of Cl, Br, or I in the sulfide solid electrolyte material effectively restrains the increase in both interface and bulk resistance, maintaining high Li ion conductivity and reducing hydrogen sulfide generation, thus enhancing the performance of lithium solid state batteries.
Implementation Method 1
the inclusion of fluorine in a sulfide solid electrolyte material restrains the increase in interface resistance
Implementation Method 2
The sulfide solid electrolyte material is so high in Li ion conductivity as to be useful for intending higher output of a battery
Implementation Method 3
the use of Cl, Br, or I in the sulfide solid electrolyte material effectively restrains the increase in both interface and bulk resistance
Data Source
AI summary
The main object of the present invention is to provide a sulfide solid electrolyte material which copes with both the restraint of the increase in interface resistance and the restraint of the increase in bulk resistance. The present invention solves the above-mentioned problems by providing a sulfide solid electrolyte material characterized by containing at least one of Cl and Br.